Why not just use a sound card for your ADC and DAC? Your average sound card
has at least 2 DAC outputs (headphone L+R), and 2 or more ADC inputs (Stereo
L+R Mic or Line input). They typically have 16-bit resolution, at 48 kHz or
better sampling rate. It's cheap (included in most motherboards), reliable,
widely available, and here is a good programming example:

http://xoscope.sourceforge.net/

they've also designed a hardware buffer to clip out-of-range inputs:

http://xoscope.sourceforge.net/hardware/hardware.html

Mark Tomich

That is something I should look into. Windows does not allow
direct hardware access so real time would be a problem but
I think there may be some support for sound in Power Basic
running under DOS.

Paul Lamar


Be cautious about using sound IO for any type of control apps. Typically there is no DC reference involved.  That is,
the signals are AC coupled into and out of the sound card. Turns out to be much cheaper to implement than real AD or
DA involving a true 0V reference.

Craig Taylor